DESCRIPTION: The objective of the Tissue Culture Core i to provide cultured cell lines to MRRC investigators to enhance their research efforts on disorders relates to MRDD. The core is a central tissue culture facility dedicated exclusively to the MRRC for establishment, maintenance and long-term storage of skin fibroblasts and lymphoblastoid cell lines for 28 MRRC investigators. Specifically, whole blood samples are used to establish EBV-transformed B lymphoblastoid cell lines, primary fibroblasts, somatic cell hybrids and other specific cell types and common cell lines are maintained for storage or growth in large quantities for biochemical/cytogenetic analysis.